This fridge came with the house, and known issues. About every two weeks we have to defrost it. So far, we have replaced all three thermistors, the defrost heater, the defrost thermistor AND (gulp) the motherfboard (the f was deliberate) because they all tested fine, and we were at a loss.

My husband refuses to replace the fan, even though the part is here. He says he can hear it turn on. Whatever

So beyond that, what else could it POSSIBLY be? Gaskets/seals :) are tight. Fridge back is clean. Damper? Or is scrap metal at this point?